Mouse spleen expression profile after systemic Candida glabrata infection

Pleiotropic type I interferons (IFNs-I) fulfil multiple protective functions during infectious diseases, but can also exert detrimental effects for the host leading to immunopathology. Here, we report that IFNs-I promote the dysregulation of Fe homeostasis in macrophage populations and in the spleen during systemic infections with the intracellular pathogen Candida glabrata, leading to fungal survival and persistence. By using microarray expression profiling with RNA isolated from mouse spleens upon systemic Candida glabrata infection and subsequent in vitro interaction experiments we show that IFN-I signaling induces global transcriptional downregulation of key players in Fe homeostasis and profoundly alters Fe transport mechanisms within macrophages. Wild-type (C57BL/6J) and Ifnar1-/- mice (8-12 weeks old) were infected intravenously (i.v.) with 5 x 10^7 colony-forming units (CFUs) of C. glabrata (ATCC2001) (in 100 μl) per 21.5 g mouse weight. On day 1, 3, 7 and 14 post-infection, spleens were collected and stored in RNAlaterTM Stabilization Solution (Thermo Fisher Scientific). Three biological replicates were done for each time point and mouse strain, respectively. Four biological replicates of PBS infected mice for each mouse strain were used as control samples and spleens were harvested 14 days post PBS injection. Organs were homogenized in 1.5 ml RNA lysis buffer (Promega) with occasional cooling on ice by using an Ika T10 basic Ultra-Turrax homogenizer (IKA). For RNA isolation, the SV Total RNA Isolation System (Promega) was used according to the manufacturer’s instructions. RNA quality was checked on RNA 6000 Nano chips (Agilent) using a Bioanalyzer 2100 (Agilent). The Low Input Quick Amp Labeling Kit (one-color) (Agilent) was used to generate fluorescent cRNA. The amplified cyanine 3-labeled cRNA samples were then purified using SV Total RNA Isolation System (Promega) and hybridized to the SurePrint G3 Mouse GE 8x60K microarray (Agilent). Microarray slides were washed and scanned with a DNA Microarray Scanner (Agilent), according to the standard protocol of the manufacturer. Information from probe features was extracted from microarray scan images using the Feature Extraction software v10.7.3 (Agilent).